Antifungal Activity of Ribosome-Inactivating Proteins.

The control of crop diseases caused by fungi remains a major problem and there is a need to find effective fungicides that are environmentally friendly. Plants are an excellent source for this purpose because they have developed defense mechanisms to cope with fungal infections. Among the plant proteins that play a role in defense are ribosome-inactivating proteins (RIPs), enzymes obtained mainly from angiosperms that, in addition to inactivating ribosomes, have been studied as antiviral, fungicidal, and insecticidal proteins.

Edodin: A New Type of Toxin from Shiitake Mushroom () That Inactivates Mammalian Ribosomes.

Ribosome-inactivating proteins (RIPs) are a group of proteins with rRNA N-glycosylase activity that irreversibly inhibit protein synthesis and consequently cause cell death. Recently, an RIP called ledodin has been found in shiitake; it is cytotoxic, strongly inhibits protein synthesis, and shows rRNA N-glycosylase activity. In this work, we isolated and characterized a 50 kDa cytotoxic protein from shiitake that we named edodin.

The Biological Action and Structural Characterization of Eryngitin 3 and 4, Ribotoxin-like Proteins from Fruiting Bodies.

Ribotoxin-like proteins (RL-Ps) are specific ribonucleases found in mushrooms that are able to cleave a single phosphodiester bond located in the sarcin-ricin loop (SRL) of the large rRNA. The cleaved SRL interacts differently with some ribosomal proteins (P-stalk). This action blocks protein synthesis because the damaged ribosomes are unable to interact with elongation factors.

Structural and functional characterization of the cytotoxic protein ledodin, an atypical ribosome-inactivating protein from shiitake mushroom (Lentinula edodes).

We have purified ledodin, a cytotoxic 22-kDa protein from shiitake mushroom (Lentinula edodes) consisting of a 197 amino acid chain. Ledodin possessed N-glycosylase activity on the sarcin-ricin loop of mammalian 28S rRNA and inhibited protein synthesis. However, it was not active against insect, fungal, and bacterial ribosomes.

Structure and Biological Properties of Ribosome-Inactivating Proteins and Lectins from Elder ( L.) Leaves.

Ribosome-inactivating proteins (RIPs) are a group of proteins with rRNA N-glycosylase activity that catalyze the removal of a specific adenine located in the sarcin-ricin loop of the large ribosomal RNA, which leads to the irreversible inhibition of protein synthesis and, consequently, cell death. The case of elderberry ( L.) is unique, since more than 20 RIPs and related lectins have been isolated and characterized from the flowers, seeds, fruits, and bark of this plant.

Isolation, Characterization and Biological Action of Type-1 Ribosome-Inactivating Proteins from Tissues of L.

Ribosome-inactivating proteins (RIPs) are known as RNA N-glycosylases. They depurinate the major rRNA, damaging ribosomes and inhibiting protein synthesis. Here, new single-chain (type-1) RIPs named sodins were isolated from the seeds (five proteins), edible leaves (one protein) and roots (one protein) of L.

Deciphering Molecular Determinants Underlying Response to Biological and Chemical Antifungal Agents by Tandem Mass Tag (TMT)-Based High-Resolution LC-MS/MS.

is a widespread pathogen responsible for the postharvest decay of citrus, one of the most economically important crops worldwide. Currently, chemical fungicides are still the main strategy to control the green mould disease caused by the fungus. However, the increasing selection and proliferation of fungicide-resistant strains require more efforts to explore new alternatives acting via new or unexplored mechanisms for postharvest disease management.

Sequence, Structure, and Binding Site Analysis of Kirkiin in Comparison with Ricin and Other Type 2 RIPs.

Kirkiin is a new type 2 ribosome-inactivating protein (RIP) purified from the caudex of with a cytotoxicity compared to that of stenodactylin. The high toxicity of RIPs from genus plants makes them interesting tools for biotechnology and therapeutic applications, particularly in cancer therapy. The complete amino acid sequence and 3D structure prediction of kirkiin are here reported.

Ebulin l Is Internalized in Cells by Both Clathrin-Dependent and -Independent Mechanisms and Does Not Require Clathrin or Dynamin for Intoxication.

Ebulin l is an A-B toxin, and despite the presence of a B chain, this toxin displays much less toxicity to cells than the potent A-B toxin ricin. Here, we studied the binding, mechanisms of endocytosis, and intracellular pathway followed by ebulin l and compared it with ricin. COS-1 cells and HeLa cells with inducible synthesis of a mutant dynamin (K44A) were used in this study.

Antiviral Activity of Ribosome-Inactivating Proteins.

Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.

Kirkiin: A New Toxic Type 2 Ribosome-Inactivating Protein from the Caudex of .

Ribosome-inactivating proteins (RIPs) are plant toxins that irreversibly damage ribosomes and other substrates, thus causing cell death. RIPs are classified in type 1 RIPs, single-chain enzymatic proteins, and type 2 RIPs, consisting of active A chains, similar to type 1 RIPs, linked to lectin B chains, which enable the rapid internalization of the toxin into the cell. For this reason, many type 2 RIPs are very cytotoxic, ricin, volkensin and stenodactylin being the most toxic ones.

Primary Sequence and 3D Structure Prediction of the Plant Toxin Stenodactylin.

Stenodactylin is one of the most potent type 2 ribosome-inactivating proteins (RIPs); its high toxicity has been demonstrated in several models both in vitro and in vivo. Due to its peculiarities, stenodactylin could have several medical and biotechnological applications in neuroscience and cancer treatment. In this work, we report the complete amino acid sequence of stenodactylin and 3D structure prediction.

Effect of an additional N-terminal methionyl residue on enzymatic and antifungal activities of Ageritin purified from Agrocybe aegerita fruiting bodies.

Ageritin, a specific ribonuclease, damaging the largest rRNA in the highly conserved α-sarcin/ricin stem-loop (SRL) has been well characterized from edible mushroom Agrocybe aegerita. Given its peculiar characteristic, Ageritin is the prototype of a new ribotoxins family expressed in basidiomycetes. In this framework, we report the characterization of Met-Ageritin, an isoform of Ageritin with an additional N-terminal methionyl residue.

Ageritin, a Ribotoxin from Poplar Mushroom ( Agrocybe aegerita) with Defensive and Antiproliferative Activities.

Ribotoxins make up a group of extracellular rRNA endoribonucleases produced by ascomycetes that display cytotoxicity toward animal cells, having been proposed as insecticidal agents. Recently, the ribotoxin Ageritin has been isolated from the basidiomycetes Agrocybe aegerita (poplar mushroom), suggesting that ribotoxins are widely distributed among fungi. To gain insights into the protective properties of Ageritin against pathogens and its putative biotechnological applications, we have tested several biological activities of Ageritin, comparing them with those of the well-known ribotoxin α-sarcin, and we found that Ageritin displayed, in addition to the already reported activities, (i) antibacterial activity against Micrococcus lysodeikticus, (ii) activity against the tobacco mosaic virus RNA, (iii) endonuclease activity against a supercoiled plasmid, (iv) nuclease activity against genomic DNA, (v) cytotoxicity to COLO 320, HeLa, and Raji cells by promoting apoptosis, and (vi) antifungal activity against the green mold Penicillium digitatum.

Antifungal Activity of α-Sarcin against Penicillium digitatum: Proposal of a New Role for Fungal Ribotoxins.

Among the putative defense proteins that occur in fungi, one of the best studied is α-sarcin, produced by the mold Aspergillus giganteus. This protein is the most significant member of the ribotoxin family, which consists of extracellular rRNA ribonucleases that display cytotoxic activity toward animal cells. Ribotoxins are rRNA endonucleases that catalyze the hydrolysis of the phosphodiester bond between G4325 and A4326 from the rat 28S rRNA.

Ebulin-RP, a novel member of the Ebulin gene family with low cytotoxicity as a result of deficient sugar binding domains.

Background: Sambucus ebulus is a rich source of ribosome-inactivating proteins (RIPs) and RIP-related lectins generated from multiple genes. These proteins differ in their structure, enzymatic activity and sugar binding specificity.

Methods: We have purified and characterized ebulin-RP from S.

Association of General and Abdominal Obesity With Hypertension, Dyslipidemia and Prediabetes in the PREDAPS Study.

Introduction And Objectives: Some anthropometric measurements show a greater capacity than others to identify the presence of cardiovascular risk factors. This study estimated the magnitude of the association of different anthropometric indicators of obesity with hypertension, dyslipidemia, and prediabetes (altered fasting plasma glucose and/or glycosylated hemoglobin).

Methods: Cross-sectional analysis of information collected from 2022 participants in the PREDAPS study (baseline phase).

Ribosomal RNA N-glycosylase Activity Assay of Ribosome-inactivating Proteins.

Ribosome-inactivating proteins (RIPs) are enzymes that irreversibly inactivate ribosomes as a consequence of their N-glycosylase (EC 3.2.2.

Purification, characterization and cytotoxicity assessment of Ageritin: The first ribotoxin from the basidiomycete mushroom Agrocybe aegerita.

Background: Several species belonging to Ascomycota phylum produce extracellular ribonucleases, known as ribotoxins, which exhibit RNase activity through the cleavage of a single phosphodiester bond, located at the universally conserved sarcin/ricin loop of the large rRNA leading to inhibition of protein biosynthesis. Clarifying the structure-function relationship in ribotoxins is interesting for their use in human tumour therapy and in construction of pest resistant transgenic plants.

Results: The ribotoxin Ageritin has been isolated for the first time from the Basidiomycetes class.

Attitudes towards insulin initiation in type 2 diabetes patients among healthcare providers: A survey research.

Aims: To describe the views of healthcare providers about starting insulin in patients with type 2 diabetes and to determine the specific factors that contribute to delay insulin initiation.

Methods: Two-phases observational descriptive study. In the quantitative phase we conducted a cross-sectional survey of a sample of 380 healthcare professionals (general practitioners (GPs), endocrinologists, internists and nurses).

Insight into the phylogenetic relationship and structural features of vertebrate myoglobin family.

Myoglobin (Mb) is studied to clarify the structure-function relationships in protein science. In this work, we report the results of a comparative analysis of amino acid sequences from 298 vertebrate Mbs. Forty-one high conserved residues were identified and seven of them were invariants [E18, G25, F43, V68, L72, H93 (proximal histidine) and H97].

Biological and antipathogenic activities of ribosome-inactivating proteins from Phytolacca dioica L.

Background: The species from the genus Phytolacca constitute one of the best sources of ribosome-inactivating proteins (RIPs) that have been used both in the therapy against virus and tumors and in the construction of transgenic plants resistant to virus, bacteria, fungi and insects. Here we investigate new activities of three representative RIPs from Phytolacca dioica (dioicin 2, PD-S2 and PD-L4).

Results: The three RIPs displayed, in addition to already reported activities, rRNA N-glycosylase activities against plant, bacterial and fungal ribosomes.

Antifungal activity of the ribosome-inactivating protein BE27 from sugar beet (Beta vulgaris L.) against the green mould Penicillium digitatum.

The ribosome-inactivating protein BE27 from sugar beet (Beta vulgaris L.) leaves is an apoplastic protein induced by signalling compounds, such as hydrogen peroxide and salicylic acid, which has been reported to be involved in defence against viruses. Here, we report that, at a concentration much lower than that present in the apoplast, BE27 displays antifungal activity against the green mould Penicillium digitatum, a necrotrophic fungus that colonizes wounds and grows in the inter- and intracellular spaces of the tissues of several edible plants.

Biological activities of the antiviral protein BE27 from sugar beet (Beta vulgaris L.).

The ribosome inactivating protein BE27 displays several biological activities in vitro that could result in a broad action against several types of pathogens. Beetin 27 (BE27), a ribosome-inactivating protein (RIP) from sugar beet (Beta vulgaris L.) leaves, is an antiviral protein induced by virus and signaling compounds such as hydrogen peroxide and salicylic acid.